1. Technical Field
The disclosed embodiments generally relate to the field of electronic document retrieval.
2. Description of the Related Art
The disclosed embodiments relate generally to the access of documents within a document repository. A document repository may be any database or other group of documents that are stored electronically and available for digital distribution. Documents within a repository may be generated in digital form by scanning devices or by multifunction devices such as those that provide scanning, printing, and/or facsimile capability. Through the use of document distribution software, the digital information that is generated by these devices may be sent to multiple applications, including document repositories. The Flowport™ software available from Xerox Corporation and described in U.S. Pat. No. 6,833,927, the disclosure of which is incorporated by reference herein in its entirety, is an example of document distribution software designed to merge paper documents into E-mail, workflow, and document management systems. It performs the functions of distributing, retrieving and storing digital documents generated by scanning paper documents. One of the features of this type of software is its ability to analyze image data for instructions regarding the handling of the document data.
The Flowport™ software is set up to scan commands from a paper user interface that is generated by the user. The user simply fills out a form and directs, by an appropriate, menu driven user interface, the multifunction process controller to recognize the machine readable digital information. Thus, paper documents containing digital information may be sent through a communications medium. U.S. Pat. No. 6,856,432, the disclosure of which is incorporated by reference herein in its entirety, describes a program storage device that is readable by a machine, where the machine has a program of instructions to extract information from a message received through, for example, a facsimile communication medium. The extracted information is used to convert the message and send the converted message through a network communication medium.
File access to documents within a controlled access document repository is currently limited to individuals having accounts on that repository and who are authorized via the access control list for the particular document that he or she wishes to retrieve. When document owners wish to provide controlled access of documents to individuals who do not have accounts on a specific repository, a copy of the document must be mailed to the individual, or the individual must be provided with an identification name/number and password that must be entered to retrieve the document electronically. It is therefore desirable to provide controlled or limited electronic access to documents in a document repository to individuals who do not have accounts on that repository.
A common method of protecting digital information that is communicated across networks is by encoding the information that is to be protected to assure access to authorized users only, and through the use of digital signatures to provide non-repudiation of the authenticity of the information. Machine readable digital information is often encoded in data glyphs on the face of the document. Data glyphs are two dimensional bar codes that can encode digital information, as described in U.S. Pat. No. 5,991,469, the disclosure of which is incorporated by reference herein in its entirety. However, bar codes or any other techniques for encoding data may be used. Data glyphs are often utilized because they possess error resistant qualities and are amenable to being used in facsimiles and printers without losing the capability of storing encoded data that may still be interpreted after being transmitted. Moreover, data glyphs also retain their error resistant qualities after repeated transmissions. A document containing data glyphs, whether represented electronically or printed in hard copy, can carry an encoded description of itself. The document may include one or more of a variety of types of fields, as well as other non-field information, and the encoded information is integrated into the electronic and printed representations of the document. In the hard copy representation of the document, this encoded information may be printed on the face of the document. In the electronic representation of the document, the encoded information may be part of the data structure of the document.
The document interpreter may read the document's field description from the document itself and, based on this description, interpret the document. U.S. Pat. No. 4,728,984, the disclosure of which is incorporated by reference herein in its entirety, describes a machine such as an electrophotographic printing machine that scans a paper document and converts or decodes the image signals located on the document for authorized users only. Where information secrecy is paramount, the document image containing the secret information may be encoded or encrypted to enable the document or document copies to be mailed or exchanged without revealing to non-authorized persons the document content. If the decoder is not enabled by a recognized authorized user, the machine duplicates the original document so that the content remains encoded.
While the availability of digital technology enables the efficient creation and distribution of digital documents, the threat of piracy is an overarching concern. A common method for guaranteeing the legitimacy of digital information is digital signature technology. Digital signature technology provides a function corresponding to conventional signatures for electronic digitized data such as documents (also referred to as multimedia data). U.S. Pat. No. 6,816,969, the disclosure of which is incorporated by reference herein in its entirety, provides a description of digital signature technology. In digital signature technology, a digital signature generator applies a private key, which the generator keeps secret, to digitized data (hereinafter referred to as message M) to be signed or a hash value thereof, a hash value being a characteristic value for the message (also referred to as a compression value or message digest). From this, a digital signature A for the message M is generated. The digital signature A is then added to the message M and made public. A digital signature verifier compares the message M or the hash value thereof to the result obtained from applying a public key corresponding to the private key to the digital signature A added to the message M. If the two do not match, the message M may have been tampered with after the digital signature A was generated. Thus, if the two do match, it confirms that the digital signature A was generated for the message M.
The disclosure contained herein describes attempts to address one or more of the problems described above.